Hach CL17sc Manuel D'utilisation page 12

3.3.1 Sample line guidelines
Select a good, representative sampling point for the best instrument performance. The sample must
be representative of the entire system.
To prevent erratic readings:
• Collect samples from locations that are sufficiently distant from points of chemical additions to the
process stream.
• Make sure that the samples are sufficiently mixed.
• Make sure that all chemical reactions are complete.
• Install the analyzer as near the sample source as possible (4.6 m (15 ft) maximum).
3.3.2 Sample requirements
The water from the sample source(s) must agree with the specifications in Specifications on page 3.
Keep the sample flow rate and operating temperature as constant as possible for best performance.
3.3.3 Drain line guidelines
N O T I C E
Incorrect installation of the drain lines can cause liquid to go back into the instrument and cause damage.
• Make sure that the drain lines are open to air and are at zero back pressure. Refer to Figure 5.
• Make the drain lines as short as possible.
• Make sure that the drain lines have a constant slope down.
• Make sure that the drain lines do not have sharp bends and are not pinched.
Figure 5 Drain lines open to air
1 Sample drain tubing 2 Drain pipe 3 Floor drain
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